<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>生成验证码</title>
  <style>
    img{
      display: inline-block;
      width: 180px;
      height: auto;
    }
  </style>
</head>
<body>
  <form action="__URL__/code_do" method="post">
    <input type="text" name="code" required/>
    <img src="{:U('verify')}" alt="" onclick="this.src='{:U('verify')}?'+Math.random()" title="看不清，再换一张">
    <button>登录</button>
  </form>
</body>
</html>